The slow speeds are because 21CN kit has given you a high target noise margin, nothing complicated, just needs provider to request a lowering of it to give you back some speed.

The target of 15dB you appear to have gives stability, but at the expense of a couple of megs of speed.

Hi,

Thanks for that - I agree and I've put it to our ISP to take forward. Although the info given here was informative and very welcome, I was sensing that there was a slightly premature push to start re-wiring everything when all of our tests etc point at the issue being on BT's side. At the moment this still seems to be the case.

Fingers crossed they sort it soon. Toes crossed that they deliver the promised FTTC without any more postponements

Thanks